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Optical properties database

If you use material type 99 in your MEDIUM_VECTOR file, data are automatically loaded from optical properties database and used as tabulated values or PLRC data, according to their definition in the database. The only parameter of the material type is therefore an unique material identifier in the optical properties database (automatically installed with GSvit and located e.g. in /share/gsvit/data/spectra/ - exact locaton depends on way how and on which OS you install GSvit).

If there are more models available, you need to choose the identifier correctly. You can use for example identifiers Ag, Ag_drude and Ag_cp for silver, where the first identifier (Ag) means tabulated optical properties (which for most of the metals won't work at visible wavelengths) and the next identifiers make choice of an dispersive model for metal treatment.

Absolute majority of the data were acquired from SOPRA database or from Refractiveindex.info web pages. This also means that absolute majority of data are tabulated, which is good for running single frequency FDTD calculation, but not good for multiple frequencies within a single FDTD run. To treat multiple frequencies in a single FDTD run, a dispersive model needs to be used (which is still in preparation).

If tabulated data from database are used, the automatically detected or user prescribed central source wavelength is used to pick (interpolate) the right values of optical parameters from the database. If the automatically detected or prescribed wavelength range does not fit the spectrum, a warning is issued and closest value is used. Note that this typically means that completely wrong value is used as the optical properties are strongly wavelength-dependent.

Adding your own spectra

Optical properties are loaded from a file, based on its name. Adding more files to the appropriate directory (e.g. in /share/gsvit/data/spectra/ - exact location depends on way how and on which OS you install GSvit) is the simplest way how to extend GSvit capabilities (sending us the file to share it with other users is even a better option).

File for defining the optical properties is a plain text file, consisting of the following fields:
file type
applicable wavelenth range in microns
reference
data corresponding to a concrete file type

Parameter "type" can be as follows:

  • sellmeier (Sellmeier formula)
  • cauchy (Cauchy formula)
  • kasarova (eight order polynom similar to Cauchy formula, odd powers only)
  • nk (n and k values tabulated)
  • drude (Drude formula)
  • cp (critical point model)
  • cp3 (critical point model CP3)

Data for different formulas are listed in order of its appearance in the formula. For tabulated data, the values are preceded by their total number. Tabulated data are interpolated when necessary.

Example of a tabulated spectrum (note that wavelength can be in other powers in meter (here nanometers), it is corrected according to range (second line of the file):

nk                   
0.163138 2.06642     
SOPRA N&K Database  
71                 
163  1.5   0.1       
...

List of available optical data

Here follows a list of all the optical properties files available in GSvit installation (25/01/2012). Absolute majority of data comes from SOPRA NK database, references for data source are given in each file separaterly. Filenames should be self-explanatory, in case of doubts see the appropriate file for description of data origin and used model:

Ag
Ag_cp
Ag_cp3
Ag_drude
Al
Al2O3
Al2O3_Palik
AlAs
AlCu
AlGaAs_0Al
AlGaAs_10Al
AlGaAs_20Al
AlGaAs_30Al
AlGaAs_40Al
AlGaAs_50Al
AlGaAs_60Al
AlGaAs_70Al
AlGaAs_80Al
AlGaAs_90Al
AlGaAs_100Al
AlGaInP_0Al
AlGaInP_10Al
AlGaInP_30Al
AlGaInP_60Al
AlGaInP_70Al
AlGaInP_100Al
AlON
AlSb
AlSi
AlSiTi
aSi
a-Si
Au
BaF2
BK7
CaF2
Carbon
CCl4
CdSe
CdTe
CO
CO2
CoSi2
Cr
Cr3Si
Cr5Si3
CrSi2El2
Cu
Cu2O
CuO
Diamond
ethanol
FeSi2_1
FeSi2_2
FeSi2_3
GaAs
GaAsO
GaP
GaP_100
GaPO
GaSb
GaSbO
Ge
Ge_100
HfO2
HfSi2
HgCdTe_0Te
HgCdTe_20Te
HgCdTe_30Te
ice
InAs
InAsO
InGaAs
InGaSb_0Ga
InGaSb_10Ga
InGaSb_30Ga
InGaSb_50Ga
InGaSb_70Ga
InGaSb_90Ga
InGaSb_100Ga
InP
InPO
InSb
INSbO
Ir
Ir3Si5_1
Ir3Si5_2
ITO
KCl
LASF9
Li
LiF
methanol
MgF2
MO
MoSi2_extraordinary
MoSi2_ordinary
NbSi_a
NbSi_b
Ni
Ni2Si
Ni3Si
NiSi
PbS
PbSe
PC
Pd
Pd2Si_extraordinary
Pd2Si_ordinary
PMMA
Pt
ReSi
SF11
Si_100
Si_110
Si_111
Si11Ge89
Si20Ge80
Si28Ge72
Si3N4
Si65Ge35
Si85Ge15
Si98Ge02
SiC
SiCr
SiGe_Ge
SiGe_Si
SiO
SiO2
Ta
TaO_1
TaO_2
Te
ThF4
Ti
TiNi
TiO2
TiSi
V
VSi2_a
VSi2_b
W
water
WSi2_a
WSi2_b
Y2O3
ZnS
ZnSe
ZnSeTe_0Te
ZnSeTe_10Te
ZnSeTe_30Te
ZnSeTe_50Te
ZnSeTe_70Te
ZnSeTe_90Te
ZnSeTe_100Te
ZrO2
ZrSi2







(c) Petr Klapetek, 2013